CA2200893A1 - A no-rinse phosphating process - Google Patents
A no-rinse phosphating processInfo
- Publication number
- CA2200893A1 CA2200893A1 CA002200893A CA2200893A CA2200893A1 CA 2200893 A1 CA2200893 A1 CA 2200893A1 CA 002200893 A CA002200893 A CA 002200893A CA 2200893 A CA2200893 A CA 2200893A CA 2200893 A1 CA2200893 A1 CA 2200893A1
- Authority
- CA
- Canada
- Prior art keywords
- phosphating solution
- phosphating
- weight
- zinc
- phosphate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
- C23C22/08—Orthophosphates
- C23C22/18—Orthophosphates containing manganese cations
- C23C22/182—Orthophosphates containing manganese cations containing also zinc cations
- C23C22/184—Orthophosphates containing manganese cations containing also zinc cations containing also nickel cations
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
- C23C22/08—Orthophosphates
- C23C22/12—Orthophosphates containing zinc cations
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
- C23C22/08—Orthophosphates
- C23C22/12—Orthophosphates containing zinc cations
- C23C22/17—Orthophosphates containing zinc cations containing also organic acids
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
- C23C22/08—Orthophosphates
- C23C22/18—Orthophosphates containing manganese cations
- C23C22/182—Orthophosphates containing manganese cations containing also zinc cations
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/34—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
- C23C22/36—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates
- C23C22/362—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates containing also zinc cations
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/34—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
- C23C22/36—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates
- C23C22/364—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates containing also manganese cations
- C23C22/365—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates containing also manganese cations containing also zinc and nickel cations
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
- C23C22/76—Applying the liquid by spraying
Abstract
A phosphatising solution and a phosphatising process by means of said phosphatising solution are preferably used to phosphatise webs of steel, zinccoated steel or aluminium strips without rinsing (no-rinse phosphatising). The phosphatising solution contains at least 2 to 25 g/l zinc ions and 50 to 300 g/l phosphate ions.
Description
2 ~008~3 A No-rinse Phosphating Process This invention relates to a phosphating solution and to a process for phosphating surfaces of steel, zinc, aluminium or their alloys. It is particularly suitable for phosphating electrolytically galvanized or hot-dip-galvanized steel. After the intended contact time on the surfaces, the 5 phosphating solutions are not rinsed off with water, but instead are immediately dried on the lines of a so-called no-rinse process. Accordingly, the process according to the invention is particularly suitable for use in continuous strip treatment plants.
The object of phosphating metals is to produce on the metal surface 10 firmly intergrown metal phosphate coatings which improve resistance to corrosion and, in conjunction with paints and other organic coatings, lead to a significant increase in paint adhesion and in resistance to creepage in corrosive environments. Phosphating processes have long been known.
Recently, low-zinc phosphating processes where the phosphating solutions 15 have comparatively low contents of zinc ions, for example of 0.5 to 2 g/l, have been particularly preferred for pretreatment in preparation for painting, more particularly electrolytic dip coating as normally applied in the automotive industry.
In the automotive industry and, in particular, in the domestic 20 appliance industry, but also for architectural applications, there has been atendency to use galvanized steel strip pre-phosphated in the steel mill in order to utilize the more favorable forming properties of phosphate-coated strip and to save on chemical treatment steps before painting. Accordingly, increasing importance is being attached to phosphating processes which 25 lead to high-quality phospl;ate coatings despite the short phosphating times of the strip mili of only a few seconds. The treatment is normally carried out by spraying, by immersion or by combined spraying/immersion, the phosphating solution being rinsed off from the metal surface with water after the required contact time. One such process is described, for example, in DE-A42 41 134, according to which phosphating solutions containing 1.0 to 6.0 9/l of zinc and 8 to 25 9/l of phosphate are used. Other optional 5 components are nickel, cobalt, manganese, magnesium and calcium each in quantities of 0.5 to 5.0 9/l, iron(ll) in quantities of up to 2 9/l and copper in quantities of 3 to 50 mg/l.
The hitherto necessary removal of the phosphating solution by rinsing off with water leads on the one hand to a high consumption of fresh water 10 in the phosphating plant and, on the other hand, results in the accumulation of wastewater contaminated with heavy metals which has to be treated for reuse or for discharge into the main drains. The concept of no-rinse phosphating has already been discussed in the literature (G. Carreras-Candi: "Characteristiques de la Phosphatation sans Rincage" .....
Surfaces 106 (1976), Number 15, pages 25-28) without any concrete information on how the process is carried out or on suitable treatment baths.
DE-C-27 39 066 describes a phosphating process which eliminates the need for rinsing with water which is undesirable from the environmental and cost point of view. In this process, the surfaces are contacted for 1 to 5 seconds at 50 to 75~C with a phosphating solution which contains 0.1 to 5 9/l of zinc, 1 to 10 parts by weight of nickel and/or cobalt per part by weight of zinc, 5 to 50 9/l of phosphate and - as accelerator - 0.5 to 5 g/l of hydrogen peroxide. The surfaces are immediately dried without rinsing.
The use of phosphating solutions containing more than 5 9/l of zinc is discouraged because they have an adverse effect on paint adhesion.
EP-B-141 341 also describes a no-rinse phosphating process. This process was developed in particular for fixed structures, such as bridges or the like. Accordingly, the surfaces to be protected are treated with a solution containing 1 to 5% by weight of zinc, 1 to 20% by weight of phosphoric acid, 0.01 to 0.5% by weight of cobalt and/or nickel and 0.02 to 220~93 1.5% by weight of an accelerator. After application of the phosphating solution, for example by wiping, brushing, spread coating, roll coating or spray coating, the solution is left to act for an unspecified time, the solutioneither reacting out or only partly reacting. In both cases, the surfaces can be rinsed after exposure to the phosphating solution.
In contrast to conventional phosphating processes which are used in preparation for painting, the phosphating solution described above has high zinc and phosphate contents. Phosphating solutions in similar concentration ranges are also known for the deposition of phosphate coatings onto metal parts which are to be subjected to cold mechanical forming, for example by drawing or pressing. The relatively thick phosphate coatings deposited, which may be impregnated with oil to enhance their effect, act as lubricants and reduce friction between tool and workpiece. They are not normally suitable as a pretreatment before painting because paint adhesion to the thick phosphate coatings under mechanical stressing is very poor. A
corresponding phosphating solution which may be used to form phosphate coatings on steel strip or steel wire, acting as a lubricant before cold drawing or other forming processes, is described for example in DE-B-25 52 122. According to this document, the solutions used contain zinc in a quantity of 5 to 100 9/l and phosphate in a quantity of 10 to 150 g/l and -as accelerator - nitrate in a quantity of 10 to 80 9/l. The phosphating solution is brought into contact with the surface for 5 to 15 seconds and then rinsed off with water.
The problem addressed by the present invention was to provide phosphating processes and phosphating solutions which are intended for use in continuous strip mills and which eliminate the need to rinse the treated surfaces with water.
In a first embodiment, the present invention relates to a process for phosphating surfaces of steel, zinc, aluminium or their alloys by treatment with acidic zinc- and phosphate-containing solutions and drying the solutions without rinsing, characterized in that the surfaces are contacted with a -phosphating solution which contains 2 to 25 g/l of zinc ions and 50 to 300 g/l of phosphate ions and which have a pH value of 1 to 4.
Zinc concentrations of 5 to 25 g/l are preferred insofar as they provide for increased process safety. If corrosion control does not have to meet overly stringent requirements, as for example in the domestic appliance field, it is suffficient to use zinc as sole layer-forming cation. Forimproved corrosion control, as required for example in automobile manufacture, it is preferred to use a phosphating process in which the phosphating solution additionally contains 2 to 25 g/l and preferably 5 to 25 g/l of manganese ions. In addition to or instead of the manganese ions, the phosphating solution may contain other components to optimize the properties of the phosphate coating for the intended application of the pretreated material. For example, the phosphating solution may additionally contain one or more divalent metal ions in quantities of 0.1 to 15 g/l, these additional metal ions preferably being selected from nickel, cobalt, calcium and magnesium. In addition, the phosphating solution may contain iron in quantities of 0.01 to 5 g/l and/or 3 to 200 mg/l of copper ions. Depending on the substrate, additions of fluoride in free or complexed form, for example as fluoro complexes of boron, silicon, titanium or zirconium, can have a favorable effect on layer formation. This is particularly the case in the phosphating of hot-dip-galvanized steel. The effective quantities of fluoride are between 0.01 and 5 g11. At pH values above 3, which can be of advantage in the surface treatment of electrolytically galvanized steel, the phosphating solutions tend to become unstable. They can be stabilized by addition of 0.1 to 100 g/l of a chelating hydroxycarboxylic acid containing 3 to 6 carbon atoms. Examples of such hydroxycarboxylic acids are lactic acid and, in particular, citric acid and tartaric acid.
The free acid content of the phosphating solution is preferably in the range from 0 to 100 points. The free acid point count is determined by titrating 10 ml of the phosphating solution with 0.1 N sodium hydroxide to a pH value of 3.6. The consumption of sodium hydroxide in ml indicates the fee acid point count. If the phosphating solution already has a pH value of 3.6, the free acid point count is thus 0. Conversely, at higher pH values, the phosphating solution is titrated with 0.1 N hydrochloric acid to a pH
value of 3.6. The free acid point count is thus negative and is equated with 5 the consumption of hydrochloric acid in ml provided with a negative symbol.
The total acid content is determined by titrating 10 ml of the phosphating solution with 0.1 N sodium hydroxide to a pH value of 8.5. The consump-tion of 0.1 N sodium hydroxide in ml indicates the total acid point count.
For the phosphating solution according to the invention, the total acid content is preferably in the range from 40 to 400 points. The ratio of free acid to total acid is preferably adjusted to lie in the range from 1:4 to 1:20.
Phosphating solutions with a temperature of 15 to 80~C and, more particularly, 20 to 40~C are preferably used. The active substance content of the phosphating solutions should be in the range from about 5.5 to about 15 35% by weight. The active substance content is defined as the sum of metal ions, phosphoric acid and any of the other components mentioned.
The process according to the invention is particularly designed for phosphating travelling metal strips in strip treatment plants as encountered, for example, in steel mills. A liquid film coating of 2 to 10 ml of phosphating 20 solution per m2 of metal surface is preferably applied to the surfaces. The optimum value for the liquid film coating is determined, on the one hand, by the active substance content of the phosphating solution and, on the other hand, by the plant-specific contact time of the phosphating solution. At the strip speeds of 10 to 300 m/minute normally encountered at the present 25 time, weights of the phosphate coatings of around 0.3 to around 3 glm2, as required for subsequent painting, are obtained with liquid film coatings of around 6 ml/m2. In general, the concentrations of the phosphating solution should be higher, the smaller the liquid film coating.
Application of the phosphating solution to the surface and adjustment 30 of the required liquid film coating can be carried out in various ways. For example, the phosphating solution may be sprayed onto the surface in such 2~300~93 a way that the required liquid film coating is established. However, greater process safety is achieved if the liquid film coating is specifically adjusted after the phosphating solution has been sprayed on, for example by blowing with compressed air or preferably by squeezing rollers. Instead of being sprayed on, the phosphating solution may also be applied to the surface by applicator rolls, in which case the required liquid film coating can be directlyadjusted. Applicator rolls are known for the surface treatment of metal strips, for example under the name of "chemcoater" or "roll coater". In addition, the process may be carried out in such a way that the surfaces dip into the phosphating solution. Metal strips may be passed, for example, through the phosphating solution, the required liquid film coating being adjusted on the surface after the strip has left the phosphating solution, for example by blowing with air or preferably by means of squeezing rollers.
The optimum process parameters are dependent upon the specific material properties of the surfaces to be treated. For example, it has been found that, in the treatment of surfaces of travelling strips of hot-dip-galvanized steel, optimal phosphating results are obtained when the phosphating solution has an active substance content of 5.5 to 35% by weight. The preferred pH value is in the range from 1.0 to 2.2 and the ratio by weight of the sum of the divalent metal ions to phosphate is preferably adjusted to a value of 1:5 to 1:6.
In the treatment of hot-dip-galvanized steel, the presence of free or complexed fluoride in the phosphating solution has a favorable effect on layer formation. Fluoride concentrations of 0.5 to 1.5 9/l are particularly effective. Free fluoride is preferably used in the form of hydrofluoric acid while complex fluorides are preferably used in the form of fluoro acids of boron, silicon, titanium and/or zirconium. Alkali metal fluoride or acidic alkali metal fluorides, such as KHF2, may also be used to make free fluoride available.
By contrast, in the treatment of surfaces of travelling strips of electrolytically galvanized steel, the best results are obtained when the ~ , ~ ', i.J 8 9 3 following conditions are established: an active substance content of the phosphating solution of 5.5 to 20% by weight, a pH value of 1.5 to 3.5, a ratio by weight of the sum of divalent metal ions to phosphate of 1:5 to 1:6.
Phosphating solutions with these bath parameters tend to become unstable, 5 particularly if the pH value is adjusted in the upper half of the range mentioned. The stability of the bath can be improved by addition of around 1 to 5% by weight of a chelating hydroxycarboxylic acid containing 3 to 6 carbon atoms, for example lactic acid and, preferably, citric acid and/or tartaric acid.
In the treatment of surfaces of travelling strips of cold-rolled, ungal-vanized steel, the following conditions are preferably established: an active substance content of the phosphating solution of 5.5 to 25% by weight, a pH value of 2.0 to 4.0, a ratio by weight of the sum of the divalent metal ions to phosphate of 1:5 to 1:6. In this case, too, bath stability can be 15 improved by addition of around 1 to 10% by weight of a chelating hydroxycarboxylic acid containing 3 to 6 carbon atoms, for example lactic acid and, pref~rably, citric acid and/or tartaric acid.
There is no need to use so-called accelerators, i.e. substances which promote layer formation by virtue of their oxidizing or reducing effect, 20 particularly in the treatment of galvanized steel. However, it can afford advantages where the development of certain crystal forms is required.
Suitable accelerators are any of the compounds known from the relevant prior art, more particularly nitrate, nitrite, chlorate, nitrobenzene sulfonic acid or hydrogen peroxide. Hydroxylamine may be used as an accelerator with 25 more of a reducing effect. Hydrogen peroxide and hydroxylamine may be used as such whereas the other accelerators mentioned may be used as free acids or in the form of salts soluble in the phosphating solution.
However, since only a small quantity of water-soluble salts, if any, should remain behind on the surface after the phosphating solution has dried, it is 30 advisable to avoid alkali metal and ammonium salts and also sulfates.
- Accelerators which do not leave salt-like residues behind on the treated 22~0893 surfaces are particularly preferred. Accordingly, hydroxylamine and, in particular, hydrogen peroxide are particularly suitable. Where accelerators are used, their preferred concentrations are from 2 to 5 g/l for hydroxylamine, nitrobenzene sulfonic acid and chlorate, from 0.2 to 1 g/l for nitrite and from 20 to 100 ppm for H2O2.
According to the invention, the liquid film remaining on the surface after application of the phosphating solution is not rinsed off, but instead is dried. To this end, the surfaces are preferably heated to a temperature of 50 to 120~C and more preferably to a temperature of 60 to 90~C. Various possibilities are available in this regard. For example, the treated steel stripmay be passed through a drying oven heated to the corresponding temper-ature. However, drying may also be carried out by blowing hot gases, preferably air, onto the surfaces and/or by exposing the surfaces to infrared radiation. Since the acidic phosphating solution can react chemically with the metal surface as long as it is still liquid, the effective contact time is defined as the time elapsing between the first contact of the surface with the phosphating solution and the complete drying of the liquid film on the surface, i.e. the end of the drying step. This time is preferably between about 3 and about 60 seconds.
Under the process conditions mentioned, phosphate coatings with a weight of 0.3 to 3 g/m2 are produced on the surfaces. Coating weights of this order are particularly desirable as a basis for subsequent painting because the two requirements of corrosion control and paint adhesion are both satisfied to a particular degree in this way. Depending on how the process is carried out, coatings are obtained which do not yield any reflexes in X-ray diffraction studies, i.e. may be regarded as X-ray amorphous, or which show more or less pronounced reflexes of hopeite.
The strips prephosphated by the process according to the invention may be used in particular in the manufacture of automobiles. It is standard practice in this regard to rephosphate and then paint the bodies (normally by cathodic electrodeposition coating) after assembly. In these cases, the ~ '008~3 material prephosphated by the process according to the invention is trans ported in the unpainted state to the further processor. To improve temporary corrosion control during storage and transportation, the phosphated material may be additionally oiled. Subsequent forming operations are also made easier in this way. Rephosphating of the assembled bodies after alkaline cleaning is readily possible.
However, phosphating in accordance with the invention may also be immediately followed by coating of the strip with an organic film or a lacquer. This process is known as coil coating. Coil-coated material is at present mainly used in the manufacture of domestic appliances such as, for example, refrigerators and washing machines and also for architectural applications.
In the prior art, it is standard practice for phosphating to be preceded by so-called activation. The object of activation is to allow crystal nuclei forthe formation of the phosphate coating to form on the metal surface. The formation of dense, small-crystal phosphate coatings is promoted in this way. At present, aqueous solutions or suspensions of titanium phosphates are exclusively used for activation. The process according to the invention may also be preceded by an activating treatment. The activating treatment may be carried out with commercially available titanium phosphate activators such as, for example, Fixodine~g) 950, a product of Henkel KGaA.
Where the process according to the invention is preceded by an activating treatment, it is advisable to dry the strip between activation and phosphating.
In another embodiment, the present invention relates to a zinc- and manganese-containing aqueous acidic phosphating solution for phosphating surfaces of steel, zinc, aluminium or their alloys, characterized in that it contains 2 to 25 g/l of zinc ions, 2 to 25 g/l of manganese ions and 50 to 300 9/l of phosphate ions and has a pH value of 1 to 4.
In addition, the phosphating solution may contain one or more of the other components mentioned above in the description of the process.
22Gu893 Similarly, the conditions mentioned above also apply to the preferred contents of Zn, Mn and any other metal ions, to the free acid and total acid contents and to the preferred ratio of free acid to total acid.
Examples Steel plates of the ST 1405 quality, steel plates electrolytically galvanized on both sides (ZE) with a zinc coating of 7.5,u and steel plates hot-dip-galvanized on both sides (Z) with a zinc coating of around 10 ~ were used for the laboratory testing of the phosphating process according to the invention. The plates all had dimensions of 10 cm by 20 cm. Before phosphating, they were degreased with a commercially available mildly alkaline cleaner (Ridoline~g) 1250 I, a product of Henkel KGaA, Dusseldorfl.
The no-rinse treatment was simulated by pouring the treatment solution into a paint thrower (Model 4302 of Lau GmbH) and applying it at 550 r.p.m. A
wet film coating of about 6 ml/m2 was formed in this way. After the treatment solution had been applied for about 5 seconds, the plates were immediately dried for about 120 seconds in a recirculating air drying cabinet heated to 75~C.
The coating weight was determined as the parameter for the phosphate coating obtained. Two different methods were used for this purpose. To determine the weight of the coating by weighing out, the plate was weighed before coating, the phosphating solution was applied and dried and the coated plate was reweighed. The coating weight in g/m2 was calculated from the weight difference. To determine the weight of the coating by dissolution, the phosphated plates were weighed, the phosphate coating was removed by dissolving with 0.5% by weight chromic acid solution and the plates were reweighed. The weight of the coating removed in g/m2 was determined from the weight difference. The coating weight determined by dissolution is generally higher than that determined by weighing out because the phosphating process converts part of the metal surface into metal phosphate. This part is not included in determination of 22;~iass3 the coating weight by weighing out, but is removed with the coating where coating weight is determined by dissolution.
Table 1 contains phosphating baths for electrolytically galvanized steel and the coating weights obtained while Table 2 contains corresponding 5 Examples for the treatment of hot-dip-galvanized steel. Phosphating solutions which lead to coating weights of 1 to 3 g/m2 are suitable for the treatment of these substrates. In the treatment baths of the Examples, zinc was used as oxide, manganese and nickel as carbonate and fluoride as sodium fluoride. Apart from water, the baths contained no other compo-1 0 nents.
For Example 20, the composition of the coating was determined in% by weight by EDX (X-ray emission): Zn 7.5, Mn 2.2, P 7.5, Al 0.3, remainder: may be recorded as oxygen.
A selection of Z plates treated in accordance with the invention was 15 subjected, as in practice, to conventional automotive rephosphating by a commercial trication phosphating process (Granodine~) 1994, a product of Henkel KGaA, Dusseldorf) and painted with a cathodic electrocoating paint (Aqualux~g) K, a product of IDAC). After a corrosion test (10 cycles of alternating climate according to VDA 621 415), the creepage of rust beneath the lacquer at a cut was measured in accordance with DIN 53167. The following results were obtained:
Example 19 1.9 mm Example 20 2.2 mm Example 22 2.4 mm Example 24 2.3 mm.
220~893 Table 1:
No-rinse Phosphating of Electrolytically Galvanized Steel Ex. Bath Composition Active pH Free Total Coating No.[9/l] Substance Acid Acid Weight' [% by weight] [points] [points] [g/m2]
210 H3PO4 85%
Zn 21.4 1.5 65 303 1.57 (W) Mn 2 105 H3PO4 85%
7.5 Zn 10.7 2.5 0.40 (W) 10.0 Mn 3 210 H3PO4 85%
Zn 21.4 2.4 31 281 1.75 (W) Mn 4 140 H3PO4 85%
10.0 Zn 14.2 2.5 0.90 (W) 13.3 Mn 1.62 (D) 5175 H3PO4 85%
12.5 Zn 17.8 2.5 29 228 1.34 (W) 16.6 Mn 1.96 (D) 6140 H3PO4 85%
10.0 Zn 14.2 2.2 0.76 (W) 13.3 Mn 1.47 (D) ~ " ~l)08~3 Table 1: (continued) Ex. Bath Composition Active pH Free Total Coating No.[9/l] Substance Acid Acid Weight [% by weight] [points] [points] [g/m2]
7140 H3PO4 85%
10.0 Zn 14.2 2.1 0.81 (W) 13.3 Mn 1.35 (D) 8110 H3PO4 85%
7.5 Zn 11.4 2.5 27 190 1.24 (D) 10.0 Mn 2.5 Ni 9110 H3PO4 85%
7.5 Zn 10.0 Mn 12.4 3.0 1.73 (D) 2.5 Ni 10.0 tartaric acid 10110 H3PO4 85%
7.5 Zn 10.0 Mn 13.4 3.5 2.05 (D) 2.5 Ni 20.0 tartaric acid 220389~
Table 1: (continued) Ex. Bath Composition Active pH Free Total Coating No.[g/l] Substance Acid Acid Weight' [% by weight] [points] [points] [g/m2]
11 100 H3PO4 85%
6 Zn 8 Mn 11.0 3.0 . 1 fluoride tartaric acid 12 110 H3PO4 85%
6 Zn 11.4 3.2 1.44 (D) 8 Mn tartaric acid 13 210 H3PO4 85%
Zn 21.4 2.2 1.8 (D) Mn 14~)210 H3PO4 85%
Zn 21.4 2.2 1.8 (D) Mn ') W: determined by weighing out D: determined by dissolution In Example 14, the plate was activated for 5 seconds before phosphating by immersion in an activating bath based on titanium phosphate (Fixo-dine(~ 950, Henke! KGaA, 0.3% in deionized water) and dried for minutes at 75~C.
~2~J893 Table 2: (continued) No-rinse Phosphating-of Hot-dip-galvanized Steel Ex. Bath Composition Active pH Free Total Coating No.[g/l] Substance Acid Acid Weight [% by weightl [points] [points] [g/m2]
15280 H3PO4 85%
Zn 27.8 1.3 81 365 0.73 (W) Mn 16560 H3PO4 85%
Zn 55.6 0.6 7.15 (W) Mn 17328 H3PO4 85%
24.0 Zn 32.6 1.1 2.72 (W) 23.4 Mn 18 305 H3PO4 85%
22.0 Zn 33.3 1.2 2.57 (W) 21.7 Mn 19 210 H3PO4 85%
15.3 Zn 20.9 1.4 73 294 1.50 (W) 15.0 Mn 210 H3PO4 85%
15 Zn 22.0 1.5 65 303 1.8 (W) 2Q Mn 22u0~3 Table 2: (continued) Ex. Bath Composition Active pH Free Total Coating No.[9/l] Substance Acid Acid Weight [% by weight] [points] [points] [g/m2]
21301 H3PO4 85%
Zn 28.7 1.0 2.63 (W) Mn 1 fluoride 22221 H3PO4 85%
Zn 22.3 1.5 67 321 1.55 (W) Mn Ni 23268 H3PO4 85%
12 Zn 25.2 1.0 2.10 (W) 12 Mn 0.8 fluoride 24 241 H3PO4 85%
10.8 Zn 22.7 1.1 1.46 (W) 10.8 Mn 0.7 fluoride 240 H3PO4 85%
20 Zn 23 1.1 1.58 (W) fluoride ') See Table 1 ~ - ~2Go~9~
Table 3:
No-rinse Phosphating of Cold-rolled Steel (ST1405) Ex Bath composition Active pH Coating No [g/l] Substance Weight' [% by weight] [glm2]
26 80 H3PO4 85% 12.4 3.0 1.4 (D) 8 Zn 8 Mn citric acid 27 74 H3PO4 85% 13 3.5 2.1 (D) 7.4 Zn 7.4 Mn 52 citric acid 28 65 H3PO4 85% 17.5 4.0 1.5 (W~
Zn Mn Fe(ll) 100 citric acid 29100 H3PO4 85% 15.8 3.0 2.3 (D) Zn Mn citric acid 3 hydroxylamine Table 3: (continued) Ex Bath composition Active pH Coating No. [g/l] Substance Weight' [% By Weight] [g/m2]
30 70 H3PO4 85% 10.5 3.5 1.8 (D) 7 Zn 7 Mn 28 citric acid 3 hydroxylamine ') See Table 1
The object of phosphating metals is to produce on the metal surface 10 firmly intergrown metal phosphate coatings which improve resistance to corrosion and, in conjunction with paints and other organic coatings, lead to a significant increase in paint adhesion and in resistance to creepage in corrosive environments. Phosphating processes have long been known.
Recently, low-zinc phosphating processes where the phosphating solutions 15 have comparatively low contents of zinc ions, for example of 0.5 to 2 g/l, have been particularly preferred for pretreatment in preparation for painting, more particularly electrolytic dip coating as normally applied in the automotive industry.
In the automotive industry and, in particular, in the domestic 20 appliance industry, but also for architectural applications, there has been atendency to use galvanized steel strip pre-phosphated in the steel mill in order to utilize the more favorable forming properties of phosphate-coated strip and to save on chemical treatment steps before painting. Accordingly, increasing importance is being attached to phosphating processes which 25 lead to high-quality phospl;ate coatings despite the short phosphating times of the strip mili of only a few seconds. The treatment is normally carried out by spraying, by immersion or by combined spraying/immersion, the phosphating solution being rinsed off from the metal surface with water after the required contact time. One such process is described, for example, in DE-A42 41 134, according to which phosphating solutions containing 1.0 to 6.0 9/l of zinc and 8 to 25 9/l of phosphate are used. Other optional 5 components are nickel, cobalt, manganese, magnesium and calcium each in quantities of 0.5 to 5.0 9/l, iron(ll) in quantities of up to 2 9/l and copper in quantities of 3 to 50 mg/l.
The hitherto necessary removal of the phosphating solution by rinsing off with water leads on the one hand to a high consumption of fresh water 10 in the phosphating plant and, on the other hand, results in the accumulation of wastewater contaminated with heavy metals which has to be treated for reuse or for discharge into the main drains. The concept of no-rinse phosphating has already been discussed in the literature (G. Carreras-Candi: "Characteristiques de la Phosphatation sans Rincage" .....
Surfaces 106 (1976), Number 15, pages 25-28) without any concrete information on how the process is carried out or on suitable treatment baths.
DE-C-27 39 066 describes a phosphating process which eliminates the need for rinsing with water which is undesirable from the environmental and cost point of view. In this process, the surfaces are contacted for 1 to 5 seconds at 50 to 75~C with a phosphating solution which contains 0.1 to 5 9/l of zinc, 1 to 10 parts by weight of nickel and/or cobalt per part by weight of zinc, 5 to 50 9/l of phosphate and - as accelerator - 0.5 to 5 g/l of hydrogen peroxide. The surfaces are immediately dried without rinsing.
The use of phosphating solutions containing more than 5 9/l of zinc is discouraged because they have an adverse effect on paint adhesion.
EP-B-141 341 also describes a no-rinse phosphating process. This process was developed in particular for fixed structures, such as bridges or the like. Accordingly, the surfaces to be protected are treated with a solution containing 1 to 5% by weight of zinc, 1 to 20% by weight of phosphoric acid, 0.01 to 0.5% by weight of cobalt and/or nickel and 0.02 to 220~93 1.5% by weight of an accelerator. After application of the phosphating solution, for example by wiping, brushing, spread coating, roll coating or spray coating, the solution is left to act for an unspecified time, the solutioneither reacting out or only partly reacting. In both cases, the surfaces can be rinsed after exposure to the phosphating solution.
In contrast to conventional phosphating processes which are used in preparation for painting, the phosphating solution described above has high zinc and phosphate contents. Phosphating solutions in similar concentration ranges are also known for the deposition of phosphate coatings onto metal parts which are to be subjected to cold mechanical forming, for example by drawing or pressing. The relatively thick phosphate coatings deposited, which may be impregnated with oil to enhance their effect, act as lubricants and reduce friction between tool and workpiece. They are not normally suitable as a pretreatment before painting because paint adhesion to the thick phosphate coatings under mechanical stressing is very poor. A
corresponding phosphating solution which may be used to form phosphate coatings on steel strip or steel wire, acting as a lubricant before cold drawing or other forming processes, is described for example in DE-B-25 52 122. According to this document, the solutions used contain zinc in a quantity of 5 to 100 9/l and phosphate in a quantity of 10 to 150 g/l and -as accelerator - nitrate in a quantity of 10 to 80 9/l. The phosphating solution is brought into contact with the surface for 5 to 15 seconds and then rinsed off with water.
The problem addressed by the present invention was to provide phosphating processes and phosphating solutions which are intended for use in continuous strip mills and which eliminate the need to rinse the treated surfaces with water.
In a first embodiment, the present invention relates to a process for phosphating surfaces of steel, zinc, aluminium or their alloys by treatment with acidic zinc- and phosphate-containing solutions and drying the solutions without rinsing, characterized in that the surfaces are contacted with a -phosphating solution which contains 2 to 25 g/l of zinc ions and 50 to 300 g/l of phosphate ions and which have a pH value of 1 to 4.
Zinc concentrations of 5 to 25 g/l are preferred insofar as they provide for increased process safety. If corrosion control does not have to meet overly stringent requirements, as for example in the domestic appliance field, it is suffficient to use zinc as sole layer-forming cation. Forimproved corrosion control, as required for example in automobile manufacture, it is preferred to use a phosphating process in which the phosphating solution additionally contains 2 to 25 g/l and preferably 5 to 25 g/l of manganese ions. In addition to or instead of the manganese ions, the phosphating solution may contain other components to optimize the properties of the phosphate coating for the intended application of the pretreated material. For example, the phosphating solution may additionally contain one or more divalent metal ions in quantities of 0.1 to 15 g/l, these additional metal ions preferably being selected from nickel, cobalt, calcium and magnesium. In addition, the phosphating solution may contain iron in quantities of 0.01 to 5 g/l and/or 3 to 200 mg/l of copper ions. Depending on the substrate, additions of fluoride in free or complexed form, for example as fluoro complexes of boron, silicon, titanium or zirconium, can have a favorable effect on layer formation. This is particularly the case in the phosphating of hot-dip-galvanized steel. The effective quantities of fluoride are between 0.01 and 5 g11. At pH values above 3, which can be of advantage in the surface treatment of electrolytically galvanized steel, the phosphating solutions tend to become unstable. They can be stabilized by addition of 0.1 to 100 g/l of a chelating hydroxycarboxylic acid containing 3 to 6 carbon atoms. Examples of such hydroxycarboxylic acids are lactic acid and, in particular, citric acid and tartaric acid.
The free acid content of the phosphating solution is preferably in the range from 0 to 100 points. The free acid point count is determined by titrating 10 ml of the phosphating solution with 0.1 N sodium hydroxide to a pH value of 3.6. The consumption of sodium hydroxide in ml indicates the fee acid point count. If the phosphating solution already has a pH value of 3.6, the free acid point count is thus 0. Conversely, at higher pH values, the phosphating solution is titrated with 0.1 N hydrochloric acid to a pH
value of 3.6. The free acid point count is thus negative and is equated with 5 the consumption of hydrochloric acid in ml provided with a negative symbol.
The total acid content is determined by titrating 10 ml of the phosphating solution with 0.1 N sodium hydroxide to a pH value of 8.5. The consump-tion of 0.1 N sodium hydroxide in ml indicates the total acid point count.
For the phosphating solution according to the invention, the total acid content is preferably in the range from 40 to 400 points. The ratio of free acid to total acid is preferably adjusted to lie in the range from 1:4 to 1:20.
Phosphating solutions with a temperature of 15 to 80~C and, more particularly, 20 to 40~C are preferably used. The active substance content of the phosphating solutions should be in the range from about 5.5 to about 15 35% by weight. The active substance content is defined as the sum of metal ions, phosphoric acid and any of the other components mentioned.
The process according to the invention is particularly designed for phosphating travelling metal strips in strip treatment plants as encountered, for example, in steel mills. A liquid film coating of 2 to 10 ml of phosphating 20 solution per m2 of metal surface is preferably applied to the surfaces. The optimum value for the liquid film coating is determined, on the one hand, by the active substance content of the phosphating solution and, on the other hand, by the plant-specific contact time of the phosphating solution. At the strip speeds of 10 to 300 m/minute normally encountered at the present 25 time, weights of the phosphate coatings of around 0.3 to around 3 glm2, as required for subsequent painting, are obtained with liquid film coatings of around 6 ml/m2. In general, the concentrations of the phosphating solution should be higher, the smaller the liquid film coating.
Application of the phosphating solution to the surface and adjustment 30 of the required liquid film coating can be carried out in various ways. For example, the phosphating solution may be sprayed onto the surface in such 2~300~93 a way that the required liquid film coating is established. However, greater process safety is achieved if the liquid film coating is specifically adjusted after the phosphating solution has been sprayed on, for example by blowing with compressed air or preferably by squeezing rollers. Instead of being sprayed on, the phosphating solution may also be applied to the surface by applicator rolls, in which case the required liquid film coating can be directlyadjusted. Applicator rolls are known for the surface treatment of metal strips, for example under the name of "chemcoater" or "roll coater". In addition, the process may be carried out in such a way that the surfaces dip into the phosphating solution. Metal strips may be passed, for example, through the phosphating solution, the required liquid film coating being adjusted on the surface after the strip has left the phosphating solution, for example by blowing with air or preferably by means of squeezing rollers.
The optimum process parameters are dependent upon the specific material properties of the surfaces to be treated. For example, it has been found that, in the treatment of surfaces of travelling strips of hot-dip-galvanized steel, optimal phosphating results are obtained when the phosphating solution has an active substance content of 5.5 to 35% by weight. The preferred pH value is in the range from 1.0 to 2.2 and the ratio by weight of the sum of the divalent metal ions to phosphate is preferably adjusted to a value of 1:5 to 1:6.
In the treatment of hot-dip-galvanized steel, the presence of free or complexed fluoride in the phosphating solution has a favorable effect on layer formation. Fluoride concentrations of 0.5 to 1.5 9/l are particularly effective. Free fluoride is preferably used in the form of hydrofluoric acid while complex fluorides are preferably used in the form of fluoro acids of boron, silicon, titanium and/or zirconium. Alkali metal fluoride or acidic alkali metal fluorides, such as KHF2, may also be used to make free fluoride available.
By contrast, in the treatment of surfaces of travelling strips of electrolytically galvanized steel, the best results are obtained when the ~ , ~ ', i.J 8 9 3 following conditions are established: an active substance content of the phosphating solution of 5.5 to 20% by weight, a pH value of 1.5 to 3.5, a ratio by weight of the sum of divalent metal ions to phosphate of 1:5 to 1:6.
Phosphating solutions with these bath parameters tend to become unstable, 5 particularly if the pH value is adjusted in the upper half of the range mentioned. The stability of the bath can be improved by addition of around 1 to 5% by weight of a chelating hydroxycarboxylic acid containing 3 to 6 carbon atoms, for example lactic acid and, preferably, citric acid and/or tartaric acid.
In the treatment of surfaces of travelling strips of cold-rolled, ungal-vanized steel, the following conditions are preferably established: an active substance content of the phosphating solution of 5.5 to 25% by weight, a pH value of 2.0 to 4.0, a ratio by weight of the sum of the divalent metal ions to phosphate of 1:5 to 1:6. In this case, too, bath stability can be 15 improved by addition of around 1 to 10% by weight of a chelating hydroxycarboxylic acid containing 3 to 6 carbon atoms, for example lactic acid and, pref~rably, citric acid and/or tartaric acid.
There is no need to use so-called accelerators, i.e. substances which promote layer formation by virtue of their oxidizing or reducing effect, 20 particularly in the treatment of galvanized steel. However, it can afford advantages where the development of certain crystal forms is required.
Suitable accelerators are any of the compounds known from the relevant prior art, more particularly nitrate, nitrite, chlorate, nitrobenzene sulfonic acid or hydrogen peroxide. Hydroxylamine may be used as an accelerator with 25 more of a reducing effect. Hydrogen peroxide and hydroxylamine may be used as such whereas the other accelerators mentioned may be used as free acids or in the form of salts soluble in the phosphating solution.
However, since only a small quantity of water-soluble salts, if any, should remain behind on the surface after the phosphating solution has dried, it is 30 advisable to avoid alkali metal and ammonium salts and also sulfates.
- Accelerators which do not leave salt-like residues behind on the treated 22~0893 surfaces are particularly preferred. Accordingly, hydroxylamine and, in particular, hydrogen peroxide are particularly suitable. Where accelerators are used, their preferred concentrations are from 2 to 5 g/l for hydroxylamine, nitrobenzene sulfonic acid and chlorate, from 0.2 to 1 g/l for nitrite and from 20 to 100 ppm for H2O2.
According to the invention, the liquid film remaining on the surface after application of the phosphating solution is not rinsed off, but instead is dried. To this end, the surfaces are preferably heated to a temperature of 50 to 120~C and more preferably to a temperature of 60 to 90~C. Various possibilities are available in this regard. For example, the treated steel stripmay be passed through a drying oven heated to the corresponding temper-ature. However, drying may also be carried out by blowing hot gases, preferably air, onto the surfaces and/or by exposing the surfaces to infrared radiation. Since the acidic phosphating solution can react chemically with the metal surface as long as it is still liquid, the effective contact time is defined as the time elapsing between the first contact of the surface with the phosphating solution and the complete drying of the liquid film on the surface, i.e. the end of the drying step. This time is preferably between about 3 and about 60 seconds.
Under the process conditions mentioned, phosphate coatings with a weight of 0.3 to 3 g/m2 are produced on the surfaces. Coating weights of this order are particularly desirable as a basis for subsequent painting because the two requirements of corrosion control and paint adhesion are both satisfied to a particular degree in this way. Depending on how the process is carried out, coatings are obtained which do not yield any reflexes in X-ray diffraction studies, i.e. may be regarded as X-ray amorphous, or which show more or less pronounced reflexes of hopeite.
The strips prephosphated by the process according to the invention may be used in particular in the manufacture of automobiles. It is standard practice in this regard to rephosphate and then paint the bodies (normally by cathodic electrodeposition coating) after assembly. In these cases, the ~ '008~3 material prephosphated by the process according to the invention is trans ported in the unpainted state to the further processor. To improve temporary corrosion control during storage and transportation, the phosphated material may be additionally oiled. Subsequent forming operations are also made easier in this way. Rephosphating of the assembled bodies after alkaline cleaning is readily possible.
However, phosphating in accordance with the invention may also be immediately followed by coating of the strip with an organic film or a lacquer. This process is known as coil coating. Coil-coated material is at present mainly used in the manufacture of domestic appliances such as, for example, refrigerators and washing machines and also for architectural applications.
In the prior art, it is standard practice for phosphating to be preceded by so-called activation. The object of activation is to allow crystal nuclei forthe formation of the phosphate coating to form on the metal surface. The formation of dense, small-crystal phosphate coatings is promoted in this way. At present, aqueous solutions or suspensions of titanium phosphates are exclusively used for activation. The process according to the invention may also be preceded by an activating treatment. The activating treatment may be carried out with commercially available titanium phosphate activators such as, for example, Fixodine~g) 950, a product of Henkel KGaA.
Where the process according to the invention is preceded by an activating treatment, it is advisable to dry the strip between activation and phosphating.
In another embodiment, the present invention relates to a zinc- and manganese-containing aqueous acidic phosphating solution for phosphating surfaces of steel, zinc, aluminium or their alloys, characterized in that it contains 2 to 25 g/l of zinc ions, 2 to 25 g/l of manganese ions and 50 to 300 9/l of phosphate ions and has a pH value of 1 to 4.
In addition, the phosphating solution may contain one or more of the other components mentioned above in the description of the process.
22Gu893 Similarly, the conditions mentioned above also apply to the preferred contents of Zn, Mn and any other metal ions, to the free acid and total acid contents and to the preferred ratio of free acid to total acid.
Examples Steel plates of the ST 1405 quality, steel plates electrolytically galvanized on both sides (ZE) with a zinc coating of 7.5,u and steel plates hot-dip-galvanized on both sides (Z) with a zinc coating of around 10 ~ were used for the laboratory testing of the phosphating process according to the invention. The plates all had dimensions of 10 cm by 20 cm. Before phosphating, they were degreased with a commercially available mildly alkaline cleaner (Ridoline~g) 1250 I, a product of Henkel KGaA, Dusseldorfl.
The no-rinse treatment was simulated by pouring the treatment solution into a paint thrower (Model 4302 of Lau GmbH) and applying it at 550 r.p.m. A
wet film coating of about 6 ml/m2 was formed in this way. After the treatment solution had been applied for about 5 seconds, the plates were immediately dried for about 120 seconds in a recirculating air drying cabinet heated to 75~C.
The coating weight was determined as the parameter for the phosphate coating obtained. Two different methods were used for this purpose. To determine the weight of the coating by weighing out, the plate was weighed before coating, the phosphating solution was applied and dried and the coated plate was reweighed. The coating weight in g/m2 was calculated from the weight difference. To determine the weight of the coating by dissolution, the phosphated plates were weighed, the phosphate coating was removed by dissolving with 0.5% by weight chromic acid solution and the plates were reweighed. The weight of the coating removed in g/m2 was determined from the weight difference. The coating weight determined by dissolution is generally higher than that determined by weighing out because the phosphating process converts part of the metal surface into metal phosphate. This part is not included in determination of 22;~iass3 the coating weight by weighing out, but is removed with the coating where coating weight is determined by dissolution.
Table 1 contains phosphating baths for electrolytically galvanized steel and the coating weights obtained while Table 2 contains corresponding 5 Examples for the treatment of hot-dip-galvanized steel. Phosphating solutions which lead to coating weights of 1 to 3 g/m2 are suitable for the treatment of these substrates. In the treatment baths of the Examples, zinc was used as oxide, manganese and nickel as carbonate and fluoride as sodium fluoride. Apart from water, the baths contained no other compo-1 0 nents.
For Example 20, the composition of the coating was determined in% by weight by EDX (X-ray emission): Zn 7.5, Mn 2.2, P 7.5, Al 0.3, remainder: may be recorded as oxygen.
A selection of Z plates treated in accordance with the invention was 15 subjected, as in practice, to conventional automotive rephosphating by a commercial trication phosphating process (Granodine~) 1994, a product of Henkel KGaA, Dusseldorf) and painted with a cathodic electrocoating paint (Aqualux~g) K, a product of IDAC). After a corrosion test (10 cycles of alternating climate according to VDA 621 415), the creepage of rust beneath the lacquer at a cut was measured in accordance with DIN 53167. The following results were obtained:
Example 19 1.9 mm Example 20 2.2 mm Example 22 2.4 mm Example 24 2.3 mm.
220~893 Table 1:
No-rinse Phosphating of Electrolytically Galvanized Steel Ex. Bath Composition Active pH Free Total Coating No.[9/l] Substance Acid Acid Weight' [% by weight] [points] [points] [g/m2]
210 H3PO4 85%
Zn 21.4 1.5 65 303 1.57 (W) Mn 2 105 H3PO4 85%
7.5 Zn 10.7 2.5 0.40 (W) 10.0 Mn 3 210 H3PO4 85%
Zn 21.4 2.4 31 281 1.75 (W) Mn 4 140 H3PO4 85%
10.0 Zn 14.2 2.5 0.90 (W) 13.3 Mn 1.62 (D) 5175 H3PO4 85%
12.5 Zn 17.8 2.5 29 228 1.34 (W) 16.6 Mn 1.96 (D) 6140 H3PO4 85%
10.0 Zn 14.2 2.2 0.76 (W) 13.3 Mn 1.47 (D) ~ " ~l)08~3 Table 1: (continued) Ex. Bath Composition Active pH Free Total Coating No.[9/l] Substance Acid Acid Weight [% by weight] [points] [points] [g/m2]
7140 H3PO4 85%
10.0 Zn 14.2 2.1 0.81 (W) 13.3 Mn 1.35 (D) 8110 H3PO4 85%
7.5 Zn 11.4 2.5 27 190 1.24 (D) 10.0 Mn 2.5 Ni 9110 H3PO4 85%
7.5 Zn 10.0 Mn 12.4 3.0 1.73 (D) 2.5 Ni 10.0 tartaric acid 10110 H3PO4 85%
7.5 Zn 10.0 Mn 13.4 3.5 2.05 (D) 2.5 Ni 20.0 tartaric acid 220389~
Table 1: (continued) Ex. Bath Composition Active pH Free Total Coating No.[g/l] Substance Acid Acid Weight' [% by weight] [points] [points] [g/m2]
11 100 H3PO4 85%
6 Zn 8 Mn 11.0 3.0 . 1 fluoride tartaric acid 12 110 H3PO4 85%
6 Zn 11.4 3.2 1.44 (D) 8 Mn tartaric acid 13 210 H3PO4 85%
Zn 21.4 2.2 1.8 (D) Mn 14~)210 H3PO4 85%
Zn 21.4 2.2 1.8 (D) Mn ') W: determined by weighing out D: determined by dissolution In Example 14, the plate was activated for 5 seconds before phosphating by immersion in an activating bath based on titanium phosphate (Fixo-dine(~ 950, Henke! KGaA, 0.3% in deionized water) and dried for minutes at 75~C.
~2~J893 Table 2: (continued) No-rinse Phosphating-of Hot-dip-galvanized Steel Ex. Bath Composition Active pH Free Total Coating No.[g/l] Substance Acid Acid Weight [% by weightl [points] [points] [g/m2]
15280 H3PO4 85%
Zn 27.8 1.3 81 365 0.73 (W) Mn 16560 H3PO4 85%
Zn 55.6 0.6 7.15 (W) Mn 17328 H3PO4 85%
24.0 Zn 32.6 1.1 2.72 (W) 23.4 Mn 18 305 H3PO4 85%
22.0 Zn 33.3 1.2 2.57 (W) 21.7 Mn 19 210 H3PO4 85%
15.3 Zn 20.9 1.4 73 294 1.50 (W) 15.0 Mn 210 H3PO4 85%
15 Zn 22.0 1.5 65 303 1.8 (W) 2Q Mn 22u0~3 Table 2: (continued) Ex. Bath Composition Active pH Free Total Coating No.[9/l] Substance Acid Acid Weight [% by weight] [points] [points] [g/m2]
21301 H3PO4 85%
Zn 28.7 1.0 2.63 (W) Mn 1 fluoride 22221 H3PO4 85%
Zn 22.3 1.5 67 321 1.55 (W) Mn Ni 23268 H3PO4 85%
12 Zn 25.2 1.0 2.10 (W) 12 Mn 0.8 fluoride 24 241 H3PO4 85%
10.8 Zn 22.7 1.1 1.46 (W) 10.8 Mn 0.7 fluoride 240 H3PO4 85%
20 Zn 23 1.1 1.58 (W) fluoride ') See Table 1 ~ - ~2Go~9~
Table 3:
No-rinse Phosphating of Cold-rolled Steel (ST1405) Ex Bath composition Active pH Coating No [g/l] Substance Weight' [% by weight] [glm2]
26 80 H3PO4 85% 12.4 3.0 1.4 (D) 8 Zn 8 Mn citric acid 27 74 H3PO4 85% 13 3.5 2.1 (D) 7.4 Zn 7.4 Mn 52 citric acid 28 65 H3PO4 85% 17.5 4.0 1.5 (W~
Zn Mn Fe(ll) 100 citric acid 29100 H3PO4 85% 15.8 3.0 2.3 (D) Zn Mn citric acid 3 hydroxylamine Table 3: (continued) Ex Bath composition Active pH Coating No. [g/l] Substance Weight' [% By Weight] [g/m2]
30 70 H3PO4 85% 10.5 3.5 1.8 (D) 7 Zn 7 Mn 28 citric acid 3 hydroxylamine ') See Table 1
Claims (15)
1. A process for phosphating surfaces of steel, zinc, aluminium or their alloys by treatment with acidic, zinc- and phosphate-containing solutions and drying the solutions without rinsing, characterized in that the surfaces are contacted with a phosphating solution which contains 2 to 25 g/l of zinc ions, 2 to 25 g/l of manganese ions and 50 to 300 g/l of phosphate ions and which has a pH value of 1 to 3.6, a free acid content of 0 to 100 points, a total acid content of 40 to 400 points and a ratio of free acid to total acid of1:4 to 1:20.
2. A process as claimed in claim 1, characterized in that the phosphating solution additionally contains one or more of the following components:
one or more additional divalent metal ions selected from Ni, Co, Ca, Mg in quantities of 0.1 to 15 g/l, copper in quantities of 3 to 200 mg/l, iron in quantities of 0.01 to 5 g/l, 0.01 to 5 g/l of fluoride in free or complexed form, 0.1 to 100 g/l of chelating hydroxycarboxylic acids containing 3 to 6 carbon atoms.
one or more additional divalent metal ions selected from Ni, Co, Ca, Mg in quantities of 0.1 to 15 g/l, copper in quantities of 3 to 200 mg/l, iron in quantities of 0.01 to 5 g/l, 0.01 to 5 g/l of fluoride in free or complexed form, 0.1 to 100 g/l of chelating hydroxycarboxylic acids containing 3 to 6 carbon atoms.
3. A process as claimed in one or more of claims 1 and 2, characterized in that the phosphating solution has a temperature of 15 to 80°C.
4. A process as claimed in one or more of claims 1 to 3, characterized in that the phosphating solution has an active substance content, defined as the sum of the metal ions and phosphoric acid, of 5.5 to 35% by weight.
5. A process as claimed in one or more of claims 1 to 4 for the treatment of surfaces of travelling metal strips.
6. A process as claimed in one or more of claims 1 to 5, characterized in that the phosphating solution is sprayed onto the surface and is adjusted to a liquid film coating of 2 to 10 ml/m2.
7. A process as claimed in one or more of claims 1 to 5, characterized in that the phosphating solution is applied to the surface by applicator rolls as a liquid film coating of 2 to 10 ml/m2.
8. A process as claimed in one or more of claims 1 to 5, characterized in that the surfaces are immersed in the phosphating solution and in that, after leaving the phosphating solution, a liquid film coating of 2 to 10 ml/m2 is adjusted on the surface.
9. A process as claimed in one or more of claims 1 to 8 for treating the surfaces of liquid strips of hot-dip-galvanized steel, characterized in that thephosphating solution has an active substance content of 5.5 to 35 % by weight, a pH value of 1.0 to 2.2 and/or a ratio by weight of (sum of divalent metal ions) to phosphate of 1:5 to 1:6.
10. A process as claimed in one or more of claims 1 to 8 for treating the surfaces of travelling strips of electrolytically galvanized steel, characterized in that the phosphating solution has an active substance content of 5.5 to 20% by weight, a pH value of 1.5 to 3.5 and/or a ratio by weight of (sum of divalent metal ions) to phosphate of 1:5 to 1:6.
11. A process as claimed in one or more of claims 1 to 8 for treating surfaces of cold-rolled ungalvanized steel, characterized in that the phosphating solution has an active substance content of 5.5 to 25% by weight, a pH value of 2.0 to 3.6 and/or a ratio by weight of (sum of divalent metal ions) to phosphate of 1:2.5 to 1:6.
12. A process as claimed in one or more of claims 1 to 11, characterized in that drying is carried out at a temperature of 50 to 120°C, the time elapsing between the first contact of the surface with the phosphating solution and the end of the drying step being 3 to 60 seconds.
13. A process as claimed in one or more of claims 1 to 12 for pretreating surfaces of steel, zinc, aluminium or their alloys to produce crystalline or X-ray-amorphous, zinc-containing phosphate coatings with a coating weight of 0.3 to 3 g/m2.
14. A zinc- and manganese-containing aqueous acidic phosphating solution for phosphating surfaces of steel, zinc, aluminium or their alloys, characterized in that it contains 2 to 25 g/l of zinc ions, 2 to 25 g/l of manganese ions and 50 to 300 g/l of phosphate ions, has a pH value of 1 to 3.6, a free acid content of 0 to 100 points, a total acid content of 40 to 400 points and a ratio of free acid to total acid of 1:4 to 1:20.
15. A phosphating solution as claimed in claim 14, characterized in that it additionally contains one or more of the following components:
one or more additional divalent metal ions selected from Ni, Co, Ca, Mg in quantities of 0.1 to 15 g/l, iron in quantities of 0.01 to 5 g/l, copper in quantities of 3 to 200 mg/l, 0.01 to 5 g/l of fluoride in free or complexed form, 0.1 to 100 g/l of chelating hydroxycarboxylic acids containing 3 to 6 carbon atoms.
one or more additional divalent metal ions selected from Ni, Co, Ca, Mg in quantities of 0.1 to 15 g/l, iron in quantities of 0.01 to 5 g/l, copper in quantities of 3 to 200 mg/l, 0.01 to 5 g/l of fluoride in free or complexed form, 0.1 to 100 g/l of chelating hydroxycarboxylic acids containing 3 to 6 carbon atoms.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4433946A DE4433946A1 (en) | 1994-09-23 | 1994-09-23 | Phosphating process without rinsing |
| DEP4433946.1 | 1994-09-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2200893A1 true CA2200893A1 (en) | 1996-03-28 |
Family
ID=6528963
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002200893A Abandoned CA2200893A1 (en) | 1994-09-23 | 1995-09-14 | A no-rinse phosphating process |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US5976272A (en) |
| EP (1) | EP0774016B1 (en) |
| JP (1) | JPH10505881A (en) |
| KR (1) | KR100347405B1 (en) |
| AT (1) | ATE182632T1 (en) |
| CA (1) | CA2200893A1 (en) |
| DE (2) | DE4433946A1 (en) |
| ES (1) | ES2135090T3 (en) |
| WO (1) | WO1996009422A1 (en) |
Families Citing this family (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19639597C2 (en) * | 1996-09-26 | 2000-01-20 | Henkel Kgaa | Process for the phosphating of running strips made of cold or hot rolled steel in high-speed conveyor systems |
| US6179934B1 (en) | 1997-01-24 | 2001-01-30 | Henkel Corporation | Aqueous phosphating composition and process for metal surfaces |
| JPH10204649A (en) * | 1997-01-24 | 1998-08-04 | Nippon Parkerizing Co Ltd | Aqueous phosphate treating solution for metallic surface and its treatment |
| US5968240A (en) * | 1997-08-19 | 1999-10-19 | Sermatech International Inc. | Phosphate bonding composition |
| DE19749508A1 (en) | 1997-11-08 | 1999-05-12 | Henkel Kgaa | Corrosion protection of galvanized and alloy galvanized steel strips |
| DE19844391C2 (en) * | 1998-09-28 | 2003-01-09 | Chemetall Gmbh | Process for preparing workpieces for cold forming |
| US6162508A (en) * | 1998-11-02 | 2000-12-19 | Nortel Networks Limited | Molybdenum phosphate based corrosion resistant conversion coatings |
| TW500827B (en) * | 1999-08-06 | 2002-09-01 | Sms Demag Ag | Process and installation for hot galvanizing of hot rolled steel strip |
| DE10010355A1 (en) * | 2000-03-07 | 2001-09-13 | Chemetall Gmbh | Applying phosphate coatings to metallic surfaces comprises wetting with an aqueous acidic phosphatizing solution containing zinc ions, manganese ions and phosphate ions, and drying the solution |
| JP2001295063A (en) * | 2000-04-10 | 2001-10-26 | Nippon Parkerizing Co Ltd | Method for forming phosphate film to nonferrous metallic material and plated steel sheet |
| DE10110834B4 (en) * | 2001-03-06 | 2005-03-10 | Chemetall Gmbh | Process for coating metallic surfaces and use of the substrates coated in this way |
| DE10110833B4 (en) * | 2001-03-06 | 2005-03-24 | Chemetall Gmbh | Process for applying a phosphate coating and use of the thus phosphated metal parts |
| US20020164425A1 (en) * | 2001-04-27 | 2002-11-07 | Rivard Douglas Charles | Method for treating iron based parts |
| US20040187967A1 (en) * | 2002-12-24 | 2004-09-30 | Nippon Paint Co., Ltd. | Chemical conversion coating agent and surface-treated metal |
| DE102005023023B4 (en) * | 2005-05-19 | 2017-02-09 | Chemetall Gmbh | Method of preparing metallic workpieces for cold forming, process coated workpieces and their use |
| JP5114834B2 (en) * | 2005-09-21 | 2013-01-09 | Ｊｆｅスチール株式会社 | Cold rolled steel sheet and method for producing the same |
| US20080283152A1 (en) * | 2007-05-17 | 2008-11-20 | Jeffrey Allen Greene | Rinse conditioner bath for treating a substrate and associated method |
| CA2686179A1 (en) * | 2007-06-07 | 2009-02-05 | Henkel Ag & Co. Kgaa | High manganese cobalt-modified zinc phosphate conversion coating |
| KR101016915B1 (en) * | 2007-11-28 | 2011-02-22 | 가부시키가이샤 고베 세이코쇼 | Aluminium alloy material with excellent surface stability and production method thereof |
| CA2902066C (en) * | 2013-03-06 | 2018-01-02 | Quaker Chemical Corporation | High temperature conversion coating on steel and iron substrates |
| EP3161176B1 (en) * | 2014-06-27 | 2018-12-19 | Henkel AG & Co. KGaA | Dry lubricant for zinc coated steel |
| KR101769302B1 (en) * | 2016-06-08 | 2017-08-18 | 현대자동차주식회사 | Composition for Phosphate Film Optimazing Mn Content and Phosphatetreatment Method of Zn Electric-Plated Steel Sheet |
| US10465292B2 (en) | 2016-10-07 | 2019-11-05 | Goodrich Corporation | Anti-corrosion and/or passivation composition for metal-containing substrates and methods for making, enhancing, and applying the same |
| DE102017207591A1 (en) * | 2017-05-05 | 2018-11-08 | Federal-Mogul Nürnberg GmbH | Steel piston with a phosphate layer |
| WO2022232815A1 (en) * | 2021-04-30 | 2022-11-03 | Ppg Industries Ohio, Inc. | Methods of making inorganic coating layers and substrates having same coating layers |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3819425A (en) * | 1972-10-18 | 1974-06-25 | Diamond Shamrock Corp | Composite coating adherent under shear condition |
| JPS50139039A (en) * | 1974-04-26 | 1975-11-06 | ||
| US3939014A (en) * | 1974-11-20 | 1976-02-17 | Amchem Products, Inc. | Aqueous zinc phosphating solution and method of rapid coating of steel for deforming |
| IT1065925B (en) * | 1976-09-03 | 1985-03-04 | Pirelli | APPARATUS TO GET THIN THIN FILAMENTS AMONG THEM |
| JPS5339945A (en) * | 1976-09-25 | 1978-04-12 | Nippon Packaging Kk | Surface treatment of zinc or zinc alloy |
| DE2905535A1 (en) * | 1979-02-14 | 1980-09-04 | Metallgesellschaft Ag | METHOD FOR SURFACE TREATMENT OF METALS |
| US4316751A (en) * | 1980-04-14 | 1982-02-23 | Hooker Chemicals & Plastics Corp. | Electrical resistance coating for steel |
| DE3023479A1 (en) * | 1980-06-24 | 1982-01-14 | Metallgesellschaft Ag, 6000 Frankfurt | PHOSPHATING PROCESS |
| GB2148950B (en) * | 1983-10-26 | 1987-02-04 | Pyrene Chemical Services Ltd | Phosphating composition and processes |
| DE3636390A1 (en) * | 1986-10-25 | 1988-04-28 | Metallgesellschaft Ag | METHOD FOR PRODUCING PHOSPHATE COATINGS ON METALS |
| DE3800834A1 (en) * | 1988-01-14 | 1989-07-27 | Henkel Kgaa | METHOD AND MEANS FOR SIMULTANEOUS SLICING, CLEANING AND PASSIVATING OF METALLIC WORKSTUFFS |
| ES2058464T3 (en) * | 1988-02-03 | 1994-11-01 | Metallgesellschaft Ag | PROCEDURE FOR THE GENERATION OF PHOSPHATE COATING ON METALS. |
| GB9207725D0 (en) * | 1992-04-08 | 1992-05-27 | Brent Chemicals Int | Phosphating solution for metal substrates |
| DE4241134A1 (en) * | 1992-12-07 | 1994-06-09 | Henkel Kgaa | Process for phosphating metal surfaces |
-
1994
- 1994-09-23 DE DE4433946A patent/DE4433946A1/en not_active Withdrawn
-
1995
- 1995-09-14 AT AT95932747T patent/ATE182632T1/en not_active IP Right Cessation
- 1995-09-14 KR KR1019970701888A patent/KR100347405B1/en not_active IP Right Cessation
- 1995-09-14 EP EP95932747A patent/EP0774016B1/en not_active Expired - Lifetime
- 1995-09-14 US US08/809,606 patent/US5976272A/en not_active Expired - Fee Related
- 1995-09-14 CA CA002200893A patent/CA2200893A1/en not_active Abandoned
- 1995-09-14 WO PCT/EP1995/003619 patent/WO1996009422A1/en active IP Right Grant
- 1995-09-14 ES ES95932747T patent/ES2135090T3/en not_active Expired - Lifetime
- 1995-09-14 DE DE59506484T patent/DE59506484D1/en not_active Expired - Fee Related
- 1995-09-14 JP JP8510571A patent/JPH10505881A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| WO1996009422A1 (en) | 1996-03-28 |
| JPH10505881A (en) | 1998-06-09 |
| EP0774016B1 (en) | 1999-07-28 |
| DE59506484D1 (en) | 1999-09-02 |
| EP0774016A1 (en) | 1997-05-21 |
| US5976272A (en) | 1999-11-02 |
| ATE182632T1 (en) | 1999-08-15 |
| KR970706420A (en) | 1997-11-03 |
| ES2135090T3 (en) | 1999-10-16 |
| KR100347405B1 (en) | 2002-12-05 |
| DE4433946A1 (en) | 1996-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5976272A (en) | No-rinse phosphating process | |
| KR100250366B1 (en) | Acid aqueous compositions and concentration in order to make zinc phosphate coating on the meal plate | |
| EP0106459B1 (en) | Phosphate coating metal surfaces | |
| US5584946A (en) | Chromium-free conversion coating treatment of aluminum | |
| US3682713A (en) | Process for applying protective coatings on aluminum,zinc and iron | |
| US20040065389A1 (en) | Method for applying a phosphate coating and use of metal parts coated in this manner | |
| CA1333147C (en) | Process of phosphating steel and/or galvanized steel before painting | |
| MXPA97003675A (en) | Compositions of zinc phosphate pararecubriment containing ox accelerators | |
| AU700492B2 (en) | Method of applying phosphate coatings to metal surfaces | |
| PT896641E (en) | COMPOSITIONS OF ZINC CONTAINING TUNGSTEN THAT USE THROTTLE ACCELERATORS | |
| CA1332910C (en) | Process of phosphating before electroimmersion painting | |
| US4486241A (en) | Composition and process for treating steel | |
| CA2373089A1 (en) | Pretreatment of aluminum surfaces with chrome-free solutions | |
| JPH04228579A (en) | Method for treating metal surface with phosphate | |
| WO2010050131A1 (en) | Treatment solution for chemical conversion of metal material and method for treatment | |
| US7208053B2 (en) | Method for applying a phosphate covering and use of metal parts thus phospated | |
| US4110129A (en) | Post treatment of conversion-coated zinc surfaces | |
| US4622078A (en) | Process for the zinc/calcium phosphatizing of metal surfaces at low treatment temperatures | |
| US5516372A (en) | Process for phosphating steel strip galvanized on one side | |
| CA2309581C (en) | Corrosion protection of steel strips coated with zinc or zinc alloy | |
| US5268041A (en) | Process for phosphating metal surfaces | |
| EP0321059B1 (en) | Process for phosphating metal surfaces | |
| JP2001508123A (en) | How to phosphate a steel band | |
| JPH10204649A (en) | Aqueous phosphate treating solution for metallic surface and its treatment | |
| JPH04507436A (en) | Method of forming a manganese-containing zinc phosphate layer on galvanized steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |